I'm a bit frustrated. I've planted several things for red fall color and this is the second fall without red.
The same native plants up on the hillsides are brilliant red and orange but mine are green and turning brown. Is there anything I can do?
Sometimes it is the genetics of the plant itself. But, if the plant has red some years and not others, then it could be the sugar content of the leaves themselves.
The best way to guarantee that you get the colors you want is to get the plants at the time of year that they would ordinately turn color. If you can see what the plant is going to look like in any given season, that is when you should get it. Same with flowers.
It is so easy to be disappointed, and plants vary considerabley.
Another thing, it depends on just where you live. If you can see the beautiful red maples in the mountains, but the same plant does not do the same on your property, it could be the microclimate.
'Fall color', I rant, is but a scam of the nursery industry, as if it is possible for your own, personal, garden to look anything like New England country side in the fall, or a mountain side of aspen and oak. I have some 200 deciduous trees on my property, and they never, ever, change color at the same time, nor lose their leaves at the same time, and it makes no difference if they are of the same species. I have green ash that are bare, yellow, and still green, all side by side.
Nope, just save those "fall color nursery dollars" and go for a drive. I went over Dallas Divide last weekend, it was spectacular.
I have marked the most vivid colored maple on the hillside above my home. Next June, I'm going to find this maple and take a softwood cutting and root it. Then I'm going to plant it in my yard. If it doesn't go red, then I'll just give up.
The development of the color (besides the genetics) is also regulated by climate. Notice that some years the aspens are really vivid ranging from bright yellow to red?
Dry weather, warm days and gradually cooling nights favor maximum development of these pigments if I remember right.
Many years this perfect weather just doesn't happen. Seems like unusually wet, and cooler weather retards development and and a good frost makes will damage leaves before pigments totally develop. Duller colors and yucky brown is about all you will get those years.
And yes, microclimate does play a role. The hillside up the road that is usually a riot of color is pretty dull this year, but the Aspens around the area are still very brightly colored.
I live pretty close to you, I think. I imagine you were looking at the oaks and maples on the mountians in the canyons. I live in Logan. Anyway, you asked what makes leaves red. A pigment. Anthocyanin. It like a dye that resides in the sugar of a plant. Here's how it works. A plant, like the Red Maple is green until the fall when the leaves turn red. Anthocyanins are in the leaves even when when the leaves are green. They are green because chlorophyll is in there too over-shadowing the red. When the temperatures drop, chlorophyll becomes less stable, breaks down, and is not replaced. The green begins to fade. Something else happens when it gets cold. A plug develops at the base of the petiole where the leaf is attached to the stem. This plug prevents the anthocyanins from leaving the leaf. The leaf is now red. Leaves that turn brilliant yellow have carotein, another photosynthetic plastid that is not so sensitive to the cold. It gets stuck in the leaf just like anthocyanin.
But, why are yours not turning? I think it's one of three things. Or, a combination of many. Or, like my turfgrass teacher used to say, 'because.' First, you live in Utah. Our soils are alkaline. Anthocyanin will appear closer to purple than red in alkaline soils. Second, the best red color comes from falls that have warm, sunny days and cool nights. We've had cool nights. But, our days have been pretty cold too. Third, cultivars. Are you sure you got a cultivar that was for red? I'm more convinced that it's our soil. I hope this wasn't too complicated for you. I might just replace your plants, if it's in your budget. Use cultivars whenever possible. This will help ensure what you will get. While you're at it, add some sulfur to your soil. This will bring down your pH. Also, have your soil tested. It could be a number of things. Let me know if any of my rambling doesn't make sense.